自从我添加了我不知道的虚拟函数后，我遇到了一个错误。你知道吗？
总共有三个错误：
- window.h:22:对"vtable for bwindow"的未定义引用
- window.cpp:16:对`vtable for bwindow的未定义引用
- window_types.cpp:22：对windows的vtable的未定义引用：：message_window
这里的错误代码文件：
window.h
#ifndef WINDOW_H_
#define WINDOW_H_
#include <string>
#include <vector>
#include "SDL/SDL.h"
#include "SDL/SDL_ttf.h"
#include "../../utils/event.h"
#include "../../utils/button.h"
using namespace std;
//ERROR HERE "undefined reference to `vtable for bwindow'"
class bwindow{
protected:
SDL_Surface* up_bar;
SDL_Surface* content;
SDL_Surface* to_blit;
SDL_Surface* text;
vector <button*> botns;
string name;
int x;
int y;
bool pressed;
int sx;
int sy;
public:
bwindow(string,int,int,int,int,int*,int*);
void graphic_update(SDL_Surface*);
void logic_update(events*);
virtual void pgu(SDL_Surface*);
virtual void plu(events*);
string get_name();
};
#endif /* WINDOW_H_ */
window.cpp:
#include <string>
#include <vector>
#include <iostream>
#include "SDL/SDL.h"
#include "SDL/SDL_gfxPrimitives.h"
#include "SDL/SDL_ttf.h"
#include "../../utils/SDL_functions.h"
#include "../../utils/event.h"
#include "../../extra_data/extra_data.h"
#include "window.h"
using namespace std;
//ERROR HERE "undefined reference to `vtable for bwindow'"
bwindow::bwindow(string title,int xp,int yp,int w,int h,int a[], int b[]){
//seting variables
x = xp;
y = yp;
sx = x;
sy = y;
name = title;
pressed = false;
//seting masks
Uint32 rmask = 0x00000000;
Uint32 gmask = 0x00000000;
Uint32 bmask = 0x00000000;
Uint32 amask = 0x00000000;
//creating up_bar
up_bar = SDL_CreateRGBSurface(SDL_SWSURFACE, w, 20, 32,rmask, gmask, bmask, amask);
SDL_FillRect( up_bar, &up_bar->clip_rect, SDL_MapRGB( up_bar->format, 0xFF, 0xFF, 0xFF ) );
boxRGBA(up_bar ,0, 0, w,20,a[0],a[1],a[2],a[3]);
//creating content area
content = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h-30, 32,rmask, gmask, bmask, amask);
boxRGBA(content,0, 0,w, h - 25,b[0],b[1],b[2], b[3]);
//adding borders
sdlf::add_border(up_bar,1,1,1,1,0,0,0,255);
sdlf::add_border(content,1,1,1,1,0,0,0,255);
//adding the up-text
SDL_Color textColor = { 0 , 0 ,0 };
TTF_Font *font;
font = fonts::load_john_han(15);
text = TTF_RenderText_Solid(font,title.c_str(),textColor);
apply_surface(20,5,text,up_bar);
//creating final surface
to_blit = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32,rmask, gmask, bmask, amask);
}
void bwindow::graphic_update(SDL_Surface* screen){
SDL_FillRect( to_blit, &to_blit->clip_rect, SDL_MapRGB( to_blit->format, 0xFF, 0xFF, 0xFF ) );
apply_surface(0,0, up_bar, to_blit);
apply_surface(0,20,content,to_blit);
apply_surface(x,y,to_blit,screen);
}
void bwindow::logic_update(events* evs){
mouse m = evs->get_mouse();
bool condition1 = m.x > x and m.x < x + up_bar->w;
bool condition2 = m.y > y and m.y < y + up_bar->h;
bool condition3 = m.left;
if (condition1 and condition2){
if (condition3 and pressed == false){
pressed = true;
sx = m.x - x;
sy = m.y - y;
}else if (not(condition3)){
pressed = false;
}
}
if (condition3 and pressed == true){
x = (m.x - sx) ;
y = (m.y - sy) ;
}
}
string bwindow::get_name(){
return name;
}
window_types.h（此文件中没有错误）
/*
* window_types.h
*
* Created on: Aug 10, 2013
* Author: newtonis
*/
#ifndef WINDOW_TYPES_H_
#define WINDOW_TYPES_H_
#include <string>
#include <vector>
#include "SDL/SDL.h"
#include "SDL/SDL_gfxPrimitives.h"
#include "SDL/SDL_ttf.h"
#include "../../utils/SDL_functions.h"
#include "window.h"
#include "../../extra_data/extra_data.h"
using namespace std;
namespace windows{
class message_window : public bwindow{
private:
vector <string> message;
string title;
public:
message_window(string,string,int a[],int b[]);
void pgu(SDL_Surface* SCREEN);
void plu(events ev);
void start(string,vector<string>,int);
void test();
};
message_window* get_message_window(string,string,int);
}
#endif /* WINDOW_TYPES_H_ */
window_types.cpp（此处为错误）
#include <string>
#include <vector>
#include <iostream>
#include "SDL/SDL.h"
#include "SDL/SDL_gfxPrimitives.h"
#include "SDL/SDL_ttf.h"
#include "../../utils/SDL_functions.h"
#include "../../utils/utilsf.h"
#include "../../extra_data/extra_data.h"
#include "window.h"
#include "window_types.h"
using namespace std;
namespace windows{
//ERROR HERE "vtable for windows::message_window"
message_window::message_window(string title,string con,int a[],int b[]) : bwindow(title, 300, 200, 150, 100,a,b){
vector <string> content_ordered;
string new_lines = "";
for (int x = 0;x < con.size();x++){
if (x < con.size()-1){
if (utilsf::cts(con[x]) == "/" and utilsf::cts(con[x+1]) == "r"){
content_ordered.push_back(new_lines);
new_lines = "";
x+=2;
}
}
if (utilsf::cts(con[x]) == ""){
new_lines = new_lines + " ";
}
new_lines = new_lines + utilsf::cts(con[x]);
if (x == con.size()-1){
content_ordered.push_back(new_lines);
}
}
SDL_Color textColor = {0, 0, 0};
TTF_Font *font = fonts::load_font1(15);
int h = 3;
for (int x = 0;x < content_ordered.size();x++){
SDL_Surface* text_surface = TTF_RenderText_Solid(font,content_ordered[x].c_str(),textColor);
apply_surface(5,h,text_surface,content);
h += text_surface->h + 3;
}
}
/*void windows::message_window::start(string title,vector <string> content,int s){
int yp = 200;
int xp = 300;
int w = 100;
int h = 50;
int a[4];
int b[4];
a[0] = utilsf::randrange(0,256,s);
a[1] = utilsf::randrange(0,256,s);
a[2] = 200;
a[3] = 255;
b[0] = 200;
b[1] = utilsf::randrange(0,256,s);
b[2] = utilsf::randrange(0,256,s);
b[3] = 255;
bwindow(title,xp,yp,w,h,a,b);
}*/
message_window* get_message_window(string title,string msj,int s){
int a[4];
int b[4];
a[0] = utilsf::randrange(0,256,s);
a[1] = utilsf::randrange(0,256,s);
a[2] = 200;
a[3] = 255;
b[0] = 200;
b[1] = utilsf::randrange(0,256,s);
b[2] = utilsf::randrange(0,256,s);
b[3] = 255;
message_window *w = new message_window(title,msj,a,b);
return w;
}
}
您需要实现void bwindow::pgu(SDL_Surface*)和void bwindow::plu(events*)，或者使它们成为纯虚拟的：
virtual void pgu(SDL_Surface*) = 0;
virtual void plu(events*) = 0;
使用纯虚拟方法，您将无法实例化bwindow对象，但可以实例化派生类型，只要这些方法是在这些类型中实现的。
点击此处查看更多关于纯虚拟方法的信息